This study was a secondary analysis of a multiwave, cross-sectional, national-level mental health screening (Saudi Mental Health Surveillance System) completed via computer-assisted phone interviews conducted in two waves between June and July 2020. The full methodology and rationale were previously published as a study protocol article [12].

Adults aged 18 years or above from Saudi Arabia were recruited via a random phone number list generated from the Sharik Association for Health Research, a research participant database [13]. The Sharik database includes individuals interested in participating in health research, currently has more than 70,000 potential participants, is growing daily, and covers the 13 administrative regions of Saudi Arabia [13].

This surveillance system used a proportional quota sampling technique to achieve an equal distribution of participants, stratified by age, gender, and region within and across the 13 administrative regions of Saudi Arabia. The Saudi Mental Health Surveillance System uses two age groups based on Saudi Arabia’s median adult age of 36 years. This led to a quota of 52 for this study.

The sample size was calculated based on the depth of the subanalysis needed for the surveillance system, which compares age and gender groups across regions with a medium effect size of approximately 0.3, 80% power, and a 95% CI [14]. Therefore, each quota group required 78 participants and a total sample of 312 per region for a grand total of 4056 participants per wave. Once the quota sample was reached, participants with similar characteristics were not eligible to participate in the study. The sampling process was controlled automatically by the data collection system with no human interference [15].

The data used in this secondary analysis included general demographic variables, such as age, gender, and region, and other health-related variables, such as a history of mental health conditions and physical activity.

Physical activity was assessed by asking the participants on how many days they performed the recommended levels, duration, and intensity of physical activities within the previous week, using two brief assessment tools for physical activity. For VIPA, the question was “how many times a week do you usually do 20 minutes or more of vigorous-intensity physical activity that makes you sweat or puff and pant?” (eg, heavy lifting, digging, jogging, aerobics, and fast bicycling). For MIPA, the question was “how many times a week do you usually do 30 minutes or more of moderate-intensity physical activity or walking that increases your heart rate or makes you breathe harder than normal?” (eg, carrying light loads, bicycling at a regular pace, and doubles tennis) [16]. The answers for these two questions ranged from 0 days in the last week to 7 days in the last week. The main mental health screening tool used for the risk of MDD was the Patient Health Questionnaire (PHQ-9) [17-20]. Risk of GAD was measured using Generalized Anxiety Disorder-7 (GAD-7) [21].

To categorize the participants’ physical activity, this study used the WHO’s global recommendations on physical activity for adults (18-64 years old), which are in line with guidelines from the Centers for Disease Control and Prevention and the American Heart Association [22,23] as follows: (1) VIPA, 75 minutes per week or (2) MIPA, 150 minutes per week. Based on participants’ self-reported responses to the interview questionnaire (ie, number of exercise minutes, frequency, and intensity level per week), two categorical outcome variables were created that reflect whether guidelines were met as follows: MIPA (1, at least 150 minutes of MIPA per week; 0, less than 150 minutes) and VIPA (1, at least 75 minutes of VIPA per week; 0, less than 75 minutes).

The PHQ-9 score is the total score of nine questions, each of which is answered on a 4-point Likert scale ranging from 0 to 3, for a final total score between 0 and 27. Similarly, the GAD-7 score is calculated as the total score of seven questions, each of which is answered on a 4-point Likert scale ranging from 0 to 3, for a final total score between 0 and 21.

Quantitative variables are presented by mean if they have a normal distribution or by median and range, as appropriate, and compared using the t test. Qualitative variables are presented as percentages and CIs and compared using Pearson chi-square test. As this study used automated electronic data collection, there are no missing values. The QPlatform also includes a data integrity check to prevent users from entering invalid data [15].

Ethical approval was obtained from the Sharik Association for Health Research institutional review board (approval number 01-2020).

The data are available from Sharik Association for Health Research upon request.

This study explored the association between WHO global recommendations on physical activity for mental health and the risks of MDD and GAD in a Saudi community population sample. It is one of the first and largest studies to explore the association between physical activity and risk of mental health disorders (MDD and GAD) in general population settings in Saudi Arabia. The study found that the average total PHQ-9 and GAD-7 scores were associated with fulfilling recommendations for MIPA among men only; however, there were no associations for VIPA in both sexes. Further analysis showed that the associations of fulfilling MIPA with PHQ and GAD were only significant for males. MIPA was associated with considerably fewer depressive symptoms in six of the nine items in the PHQ-9. Moreover, MIPA was associated with considerably fewer anxiety symptoms in six of the seven items in the GAD-7 scale. None of the anxiety symptoms (GAD-7 items) was associated with VIPA. On the other hand, VIPA was associated with considerably fewer depressive symptoms in three of the nine items in the PHQ-9. However, VIPA was associated with more depressive symptoms in the self-harm and suicide ideation item of the PHQ-9.

MIPA has been shown to have a significant association with better mental health in several other studies across many countries, confirming its cross-cultural effectiveness [2,4,8]. According to recent meta-analysis study findings, MIPA has significant effects on the severity of depressive symptoms among nonclinical populations (age >18 years) after supervised or unsupervised training. This effect of even low-intensity physical activity may be attributable to the exercise-induced release of neurotrophic growth factors that are responsible for nerve growth and synaptic plasticity in the brain [24]. However, other studies found different effects of physical activity on mental health in relation to gender [26].

VIPA is generally associated with better mental well-being, including coping, autonomy, and personal growth [26,27]. However, some evidence suggests that VIPA may have no association with depression and anxiety, although VIPA is associated with better scores for some depressive symptoms [27-30]. One explanation is that VIPA may be associated with more negative affective states during participation, compared with MIPA, which can predict dropout and therefore reduce the likelihood of meeting physical activity guidelines [2,31]. In addition, the strenuous nature of VIPA may also undermine competence, particularly for those who are inactive [2,31]. Finally, due to its extreme nature, VIPA may not be suitable for everyone and, apart from a few experimental studies, might not be adopted for enough time to show effects on MDD and GAD in the general population.

One strength of this study was the exploration of the association between physical activity and individual symptoms of depression/anxiety, as mental health symptoms may differ in their etiology, risk factors, impairment, etc, and thus may show differential associations with physical activity [11,25]. Analyzing individual symptoms and their causal associations is an initial step toward personalized treatment of mental health disorders that recognizes the heterogeneity of MDD and GAD [11]. A previous study explored the association between individual symptoms of MDD and physical activity and found that eight out of 26 symptoms were relevant in young adults diagnosed with MMD [25].

This study was limited by its cross-sectional design, which prevented the analysis from generating the direction of the association between physical activity and the risks of MDD and GAD. The study was also limited by its bivariate analysis, which may be affected by other behavioral factors. However, it provided initial insights on the effect of physical activity on mental health in a general community setting in Saudi Arabia, which adds to the global literature in this area of research. The findings of this study may be relevant to other countries with high levels of physical inactivity like Saudi Arabia, but generalization of the results to other countries may be limited.

This study found that fulfilling guidelines on MIPA (150 min/week) is associated with lower depression scores among male participants and generally fewer depressive and anxiety symptoms. Increasing the general population’s awareness of the need to increase moderate physical activity levels may improve the population’s mental health.